ISDI: Understanding inert waste storage facilities, their obligations and alternatives
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Time to read 7 min
Summary
Introduction What is an ISDI? History and regulatory evolution Thresholds to be met for ISDI admission Alternatives in case of exceeding these thresholds: ISDI+, ISDND and ISDD The central role of analyses and the BRGM guide Alternatives to landfill: on-site and off-site reuse Traceability and the Trackdéchet digital tool Economic and environmental issues related to ISDI Frequently Asked Questions (FAQ) Why trust Pouryère for your soil analysis? To learn more
Introduction
In a world where construction and renovation generate millions of tons of waste each year, waste management has become an essential issue. Among the regulated solutions, the ISDI (Inert Waste Storage Facility) plays a crucial role. Often perceived as a simple rubble dump, it is in fact a key component of the French environmental system.
This article offers an in-depth look at the world of hazardous waste landfills: their definition, regulatory framework, soil analysis , thresholds, and alternatives such as on-site or off-site reuse. The aim is to provide a clear, educational, and comprehensive overview for construction professionals, project owners, and planning stakeholders.
What is an ISDI?
An ISDI is a classified installation for environmental protection (ICPE) intended for the storage of so-called inert waste. This waste has a particular characteristic: it does not decompose, does not burn and does not produce harmful chemical or biological reactions once buried.
In practical terms, an ISDI (Integrated Storage Facility for Hazardous Materials) accepts materials such as:
Raw or crushed concrete, not contaminated.
Bricks, tiles, ceramics.
Natural, unpolluted stones and soil.
Demolition rubble, after sorting and without the presence of asbestos.
An ISDI is therefore not a “construction site dump”, but a regulated site, subject to prefectural authorization, with strict environmental monitoring (control of leachate, management of rainwater, traceability of inputs).
History and regulatory evolution
The concept of ISDI (Inert Waste Disposal Facility) was introduced in France in the 2000s, in connection with the evolution of European waste law. Before that, inert waste was often buried in unregulated landfills, with risks of pollution.
The decree of December 12, 2014 constitutes the reference text:
It defines the admission thresholds for ISDI.
It specifies the procedures for managing the sites (controls, traceability, environmental monitoring).
It is in line with European directives on waste prevention and the protection of soil and groundwater.
Since then, the regulations have been regularly updated to clarify admission criteria and strengthen controls.
The thresholds to be met to be admitted to ISDI
Waste is only accepted at an ISDI (Industrial Waste Disposal Facility) if it meets strict thresholds. These thresholds relate to the content of pollutants and their solubility. Here is a summary table:
| Parameter analyzed | ISDI threshold (mg/kg DM) |
|---|---|
| Sulfates | ≤ 1000 |
| Fluorides | ≤ 10 |
| Arsenic, Lead, Chromium | ≤ 0.5 |
| Cadmium | ≤ 0.04 |
| total PAHs | ≤ 30 |
| Total PCBs | ≤ 1 |
Alternatives in case of excess: ISDI+, ISDND and ISDD
When the thresholds are exceeded, several options exist:
ISDI+ : for lands slightly above the thresholds, particularly rich in sulfates (gypsum areas) or fluorides.
ISDND (Non-Hazardous Waste Storage Facility) : for non-hazardous but polluted waste (high hydrocarbons, sulfates…).
ISDD (Hazardous Waste Storage Facility) : for hazardous waste (high content of PAHs, heavy metals, solvents, etc.).
| Sector | Typical thresholds | Accepted waste | Observation |
|---|---|---|---|
| ISDI | Sulfates ≤ 1000, Fluorides ≤ 10, Metals ≤ 0.5… | Concrete, clean land | Cheapest option |
| ISDI+ | Sulfates ≤ 8,000, Fluorides ≤ 150 | Sulfate or fluoride soils | Specific sites |
| ISDND | Sulfates ≤ 20,000, Hydrocarbons ≤ 2,500 | Non-hazardous polluted waste | High cost |
| ISDD | No fixed threshold (adapted to the substances) | Hazardous waste | The most demanding sector |
The central role of analyses and the BRGM guide
Analyses form the basis of any approach to the management of excavated material. They serve to identify the possible presence of invisible pollutants (soluble salts, heavy metals , hydrocarbons, PCBs) and to decide on the correct disposal channel: ISDI, ISDI+, ISDND or ISDD.
The BRGM recommends a simple rule: 1 analysis per 1,000 m³ excavated , in order to guarantee the representativeness of the materials and limit the risks of errors.
Beyond storage, the BRGM has paved the way for on-site and off-site reuse . In some cases (unpolluted soils with similar geochemical profiles), it is possible to reuse the soil without systematic analysis, thanks to the available reference maps. In other cases, a multi-tiered process guides the studies and authorizes reuse as long as the materials do not pose a risk to the environment.
Thus, analyses are not just a regulatory obligation: they are a decision-making tool , enabling us to combine legal compliance, optimization of construction costs and implementation of sustainable solutions in the spirit of the circular economy.
Alternatives to storage: on-site and off-site reuse
While landfilling remains the most well-known solution for managing inert waste, it is not always the most suitable. Regulations and BRGM guidelines now encourage recovery solutions that reduce costs, limit environmental impact, and align with a circular economy approach. Two main options stand out: on-site reuse and off-site reuse.
On-site reuse
The first alternative is to reuse the excavated soil directly on the site where it was produced .
Example: using excavated material to backfill areas, create terrain models, fill trenches or develop green spaces.
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Benefits :
Completely avoids the costs and impacts of transportation to a storage facility.
Reduces purchases of new materials (sands, gravels, aggregates).
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It simplifies administrative management since the soil does not leave the site.
However, this solution is conditional on two essential points:
Technical compatibility (geotechnical quality of the land, absence of pollutants).
Compliance with the development plan (no unplanned overfilling, compliance with elevations).
Off-site reuse
When land cannot be fully reused on its original site, another option exists: to utilize it on another construction site or development project .
The BRGM has published several reference guides outlining this process. According to these documents:
If the soils come from an unpolluted site and are geochemically compatible with the receiving site (thanks to geochemical anomaly maps), they can be reused without systematic analyses .
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In other cases, a three-level process requires comparative analyses to be carried out between the excavated material and the receiving soil in order to guarantee the absence of negative impact on the environment.
Examples of uses include:
Quarry filling.
Backfilling as part of road projects.
Landscaping (embankments, retention basins).
Traceability and the Trackdéchet digital tool
Construction and demolition waste management is not solely based on analytical thresholds and the choice of disposal channel: administrative traceability is just as essential. Since January 1, 2022, the French government has implemented the Trackdéchet digital platform, which is mandatory for many waste streams.
This tool allows you to:
To generate and electronically sign the BSD (Waste Tracking Forms) .
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To trace waste from its production on site to its disposal in ISDI, ISDI+, ISDND or ISDD.
To secure exchanges between producers, transporters and landfill operators.
Having a history that can be consulted at any time facilitates controls and reduces the risk of administrative errors.
In practice, each batch of excavated material sent to an ISDI (Industrial Waste Disposal Facility) must be accompanied by a digital waste tracking form (BSD) on Trackdéchet. This system guarantees complete transparency , prevents illegal dumping, and aligns with the government's digitalization of the waste management sector.
The economic and environmental challenges linked to ISDI
The economic stakes
Managing excavated materials represents a major expense for construction sites. Directing materials to the correct recycling stream is therefore not only a regulatory issue, but also a lever for budget optimization .
Differentiated cost of the channels : sending excavated material to ISDI is significantly cheaper than to ISDND or ISDD, where taxes and processing costs are much higher.
Reduction of volumes removed : thanks to analyses, some materials can be reused on site or recovered off site, reducing the tonnage sent to storage and therefore the bill.
Anticipation and planning : early diagnosis helps avoid additional costs related to poor land orientation (for example, refusal at landfill due to insufficient analysis, requiring trucks to be redirected urgently).
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Circular economy : reusing excavated soil as backfill or shaping material avoids the purchase of new aggregates, generating a direct economic gain.
In short, rigorous management via the ISDI Pack is not just an administrative burden: it is a smart investment that helps secure the construction site and reduce its costs.
Environmental issues
Beyond the regulations, the primary issue is environmental . ISDI facilities, like all storage facilities, must guarantee the protection of soils and groundwater.
Limiting pollution : the requirement for analyses makes it possible to detect invisible pollutants and prevent their dispersion in the environment.
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Preserving natural resources : by promoting the reuse of excavated soil on site or off site, we reduce the use of quarries and the extraction of aggregates.
Reducing the carbon footprint : less waste disposed of = fewer truck journeys to landfills, and therefore a reduction in transport-related emissions.
To be part of a circular economy : each tonne of soil recovered is a resource reintegrated into the cycle, and not waste condemned to landfill.
Ultimately, the ISDI system lies at the crossroads of two logics: securing construction sites economically and ensuring responsible soil management from a sustainability perspective.
The author of the article: Joseph OLIVIER
Joseph Olivier is an entrepreneur in the environmental sector. Originally from Nantes, he trained in waste management before creating a circular economy consulting firm . In 2022, he co-founded Pouryère with the ambition of addressing citizens' concerns about soil quality in France and access to environmental data.
Frequently Asked Questions (FAQ)
What is inert waste?
A material that does not react chemically or biologically (concrete, clean soil, sorted rubble).
How long has the ISDI regulation existed?
The founding texts date from the early 2000s, with a framework reinforced by the decree of December 12, 2014.
Why is an analysis mandatory?
Because “apparently inert” materials can contain invisible pollutants (sulfates, heavy metals).
What is the ISDI Pack?
A service combining sampling, laboratory analyses, and a report to justify admission to ISDI.
Why trust Pouryère for your soil analysis?
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